Prior seats of this type comprise an inner frame for taking up any loads which are active on the seat and an outer covering for appropriately defining the shape of the seat. In this context it is known to produce the carrying frame, for example as a welded construction of light metal tubes or profile sections, or as a cast part of a corresponding light metal alloy.
For the welded construction a relatively large number of separate parts must be produced, prepared, and connected with each other in several welding operations, whereby this manner of production entails a high labor cost.
In the case where the carrying parts of the seat are produced as cast parts, the possibility exists to construct the respective part as a single component with all the details. However, it must also be considered that, for cast parts for reasons of material strength, material additions are necessary which have a disadvantageous effect with regard to the weight. Besides, cast parts still require a milling operation. Furthermore, on the one hand the use of the die casting process is only economically worthwhile for relatively large numbers of parts due to the high costs of a corresponding mold, and on the other hand, the use, for example, of a high quality casting process entails high labor costs even for small numbers of parts.
Because of the permit requirements for seats in aircrafts, the production thereof requires exhaustive production controls including X-ray examinations of welded constructions and of cast parts.
It has been observed that prior seats of this type have the habit that, after the seat has been pivoted into its recess, the seat could tilt itself out of its recesses again, if the pivoting into the recess is not carried out according to the proper method, that is to say, until secure locking is achieved Thus, in an emergency situation the seat might block an important escape route or hinder rescue measures